Archaeologists find evidence of early human infrastructure in submerged Spanish cave

Asubmerged bridge created by ancient humans has been uncovered in a cave on the Spanish island of Mallorca, offering new insights into the timeline of human colonization in the western Mediterranean, according to a report by Independent.

Archaeologists found the 25-foot submerged bridge in a cave on the Spanish island of Mallorca, providing the earliest confirmed evidence of human presence in the area.  Mallorca, the sixth-largest island in the Mediterranean, was one of the last to be settled by humans. 

Previous research, analyzing archaeological evidence such as charcoal, ash, and bones, suggested that human settlement on the island began around 4,400 years ago. Other studies have proposed evidence of human presence on Mallorca as early as 9,000 years ago, but these claims have been disputed due to inconsistencies. 

Recently, a cave near the island's coast was found to contain passages flooded by rising sea levels, with distinct calcium-rich deposits forming on it during periods of high sea level.  Past studies have shown that such calcium deposits, along with coloration bands on submerged human-made structures, can serve as indicators for tracking historical sea-level changes.

By analyzing these encrusted deposits and light-colored bands on the bridge, the research, published in the journal Communications Earth and Environment, estimated the bridge's construction to be around 6,000 years ago. This new date is over two thousand years earlier than previous estimates of the initial human settlement on the western Mediterranean island, according to the researchers.

"The discovery of this submerged bridge and other artifacts suggests a high level of sophistication, indicating that early settlers were aware of the cave's water resources and constructed infrastructure strategically to navigate them," said Bogdan Onac, a co-author of the study. The revised timeline for human settlement on Mallorca also aligns with ancient environmental events on the island, such as the extinction of the goat-antelope species Myotragus balearicus. 

"This research highlights the value of interdisciplinary collaboration in uncovering historical realities and enhancing our understanding of human history," Dr. Onac added. Scientists plan to continue exploring Mediterranean cave systems using similar techniques. They aim to study caves formed millions of years ago to identify preindustrial sea levels and assess the impact of contemporary climate change on rising sea levels.